Imaging device and plate spring

ABSTRACT

Disclosed herein is an imaging device including: a lens case on which a lens is installed; a columnar member having a central axis coincidental with a rotational axis of the lens case and formed on a lateral surface of the lens case, the rotational axis extending in a tilt direction being an in-plane direction perpendicular to a horizontal direction; a base supporting the lens case so as to be turnable in the tilt direction; and a plate spring secured to the base and pressing a circumferential surface of the columnar member toward the base by elastic force.

BACKGROUND

The present technology relates to an imaging device and a plate spring.

Imaging devices such as security cameras and the like are used to take apicture of surrounding environment but have a fixed installationposition. Therefore, a lens of the imaging device is desirably movedhorizontally and vertically depending on the relationship between arange capable of being shot through the lens installed in the securitycamera and a site to be shot by a user by use of the security camera.Incidentally, the horizontal movement of a lens is referred to as themovement in a pan direction and the vertical movement of the lens isreferred to as the movement in a tilt direction.

A security camera is generally composed of a lens block or a memberincluding a lens and a support member for supporting the lens block andsecuring a main body to a ceiling or the like in a room. In this case,the lens block can be moved in pan and tilt directions with respect tothe support member.

SUMMARY

A lens block has heretofore been positioned in pan and tilt directionsby e.g. a ball joint, a universal joint or the like. However, such amechanism has a complicated structure and needs a large space forinstallation of component parts. In addition, such a structure needs alarge number of screws for the installation of the component parts.Consequently, it is hard to achieve downsizing and cost reduction in themanufacture of the imaging device.

It is desirable to provide a noble and improved imaging device and platespring that can achieve the downsizing of the whole, and change thedirection of a lens and secure the position of the lens with a simpleconfiguration.

According to an embodiment of the present disclosure, there is providedan imaging device including: a lens case on which a lens is installed; acolumnar member having a central axis coincidental with a rotationalaxis of the lens case and formed on a lateral surface of the lens case,the rotational axis extending in a tilt direction being an in-planedirection perpendicular to a horizontal direction; a base supporting thelens case so as to be turnable in the tilt direction; and a plate springsecured to the base and pressing a circumferential surface of thecolumnar member toward the base by elastic force.

The plate spring may have a first bent portion pressing thecircumferential surface of a columnar member toward the base.

The plate spring may further have a plate-like insertion portion, andthe base may have a first opening adapted to receive the insertionportion inserted thereinto to secure the plate spring.

The imaging device may further include a cover allowing the lens to beexposed and covering the lens case, the columnar member, the base andthe plate spring; and the plate spring may secure the cover to the baseby elastic force.

The cover may support the lens case turnably in the tilt direction.

The plate spring may have a second bent portion securing the cover tothe base.

The cover may have a second opening adapted to receive the plate springinserted thereinto and a guide portion guiding the plate spring to thesecond opening.

According to another embodiment of the present disclosure, there isprovided a plate spring including: a first spring portion pressing acircumferential surface of a columnar member toward a base supportingthe lens case, the columnar member being formed on a lateral surface ofa lens case on which a lens is installed; and a second spring portionsecuring a cover to the base by elastic force, the cover covering thelens case, the columnar member and the base while allowing the lens tobe exposed.

The plate spring may further include a plate-like insertion portioninserted into a first opening formed in the base.

The present disclosure described above can downsize the whole of thedevice and change and fix the direction and position of the lens withthe simple configuration.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a security camera according to anembodiment of the present disclosure;

FIG. 2 is a lateral view of the security camera according to theembodiment;

FIG. 3 is a perspective view of the security camera according to theembodiment with an exterior cover removed;

FIG. 4 is an exploded perspective view of the security camera shown inFIG. 3;

FIG. 5 is an exploded lateral view of the security camera shown in FIG.3;

FIG. 6 is an exploded lateral view of the security camera shown in FIG.3;

FIG. 7 is an exploded perspective view of the security camera accordingto the embodiment with exterior covers removed;

FIG. 8 is an exploded perspective view of a lens block;

FIG. 9 is a plan view of a pan plate spring;

FIG. 10 is a lateral view of the pan plate spring;

FIG. 11 is a plan view of a tilt plate spring;

FIG. 12 is a lateral view of the tilt plate spring;

FIG. 13 is a lateral view of the tilt plate spring;

FIG. 14 is a perspective view of the exterior cover;

FIG. 15 is a bottom view of the exterior cover; and

FIG. 16 is a partial enlarged view of FIG. 6, illustrating a state wherethe tilt plate spring holds a projecting portion of a lens case.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present disclosure will hereinafter bedescribed in detail with reference to the accompanying drawings.Incidentally, in the present specification and drawings, constituentelements having substantially identical functional configurations aredenoted with like reference numerals and their duplicate explanationsare omitted.

Descriptions are given in the following order.

1. A configuration in an embodiment

2. An assembly method in the embodiment

3. An adjustment method in the embodiment

<1. Configuration in the Embodiment>

A description is first given of a security camera 100 according to anembodiment of the present disclosure.

The security camera 100 is secured to a horizontal plane such as e.g. aceiling of a room or the like. The security camera 100 takes photos ofsurrounding environment as moving images or still images. As illustratedin FIGS. 1 and 2, a lens 108 c of the security camera 100 can manuallybe shifted in horizontal and vertical directions. Incidentally, thehorizontal movement of the lens 106 c is referred to as the movement ina pan direction and the vertical movement of the lens 108 c is referredto as the movement in a tilt direction. Adjusting the position of thelens 108 c installed in the security camera 100 can take a photo of asite to be shot by a user with the security camera 100 regardless of arange capable of being shot through the lens 108 c.

The security camera 100 includes a lens block 101 covered by an exteriorcover 107; an lower case 103 covered by the exterior cover 109; and acircuit board 104, on which electronic parts such as circuits requiredto operate the security camera 100 are mounted.

Referring to FIG. 7, the lens block 101 is composed of a base 105 and alens case 108. A description is first given of the lens block 101.

The base 105 is made of e.g. a synthetic resin. Referring to FIG. 8,lens case support portions 105 b support the lens case 108 so as to beturnable in the tilt direction. The lens case support portion 105 b hasa circumferential surface, which corresponds to the circumferentialsurface of a slide portion 108 a of the lens case 108. In this way, thelens case 108 can smoothly travel in the tilt direction. The base 105 isput on three projecting portions 103 a and turned thereon in the pandirection. In addition, the base 105 supports the lens case 108 so as tobe turnable in the pan direction. Further, the base 105 has an outercircumferential portion 105 a formed in a circular cylindrical shape.The outer circumferential portion 105 a is pressed against the lowercase 103 side by a pan plate spring 102.

The lens case 108 is made of e.g. a synthetic resin. In addition, thelens 108 c is installed on the lens case 108. A CCD (Charge CoupledDevice) imaging element or a CMOS (Complementary Metal OxideSemiconductor) imaging element or other electric parts are installedinside the lens case 108; however, illustration is omitted in thefigures. The COD imaging element or the CMOS imaging element is adaptedto focus light passing through the lens 108 c into an image and subjectthe image to photoelectric conversion to create signals. The lens case108 is formed with projecting portions 108 b on its lateral surfaces.The projecting portion 108 b is an example of a columnar member and hasa central axis coincident with the tilt-directional rotational axis ofthe lens case 108. The lens case 108 can be turned in the tilt directionon the base 105.

A tilt plate spring 106 is made of e.g. metal. The tilt plate spring 106is secured to the base 105 and presses the circumferential surface ofthe projecting portion 108 b of the lens case 108 toward the base 105 byelastic force. The tilt plate spring 106 secures the exterior cover 107to the base 105 by the elastic force.

The tilt plate spring 106 includes bent portions 106 a, 106 b and aninserting portion 106 c. The bent portion 106 a is an example of a firstbent portion and presses the circumferential surface of the projectingportion 108 b toward the base 105 by the elastic force of the platespring. The bent portion 106 b is an example of a second bent portion.In addition, the bent portions 106 b are inserted into correspondingsecuring holes 107 a of the exterior cover 107 to secure the exteriorcover 107 to the base 105 by the elastic force of the plate spring. Theinserting portion 106 c is formed like a plate. In addition, theinserting portion 106 c is formed with an insertion side end portion onthe bent portion 106 a side and is inserted into an insertion hole 105 cof the base 105. Consequently, the tilt plate spring 106 is secured tothe base 105.

The pan plate spring 102 is made of e.g. metal. In addition, the platespring 102 presses the base 105 toward the lower case 103 by elasticforce. The pan plate spring 102 includes spring portions 1020, acircular portion 102 d, and retaining portions 102 e. The circularportion 102 d is a thin plate and has a ring shape. The base 105 isinserted into the inner circumference of the circular portion 102 d.Since the circular portion 102 d is formed with cutout portions 102 f atits inner circumference, the spring portion 102 c has appropriateelastic force and presses the outer circumferential portion 105 a of thebase 105 by the elastic force. The retaining portion 102 e is formed bybeing bent from the outer circumference of the circular portion 102 dand retains the corresponding projecting portion 103 a.

In the state where the security camera 100 is assembled, the lens block101 is pressed by the pan plate spring 102 against the projectingportions 103 a of the lower case 103 serving as a chassis of thesecurity camera 100. The outer circumferential portion 105 a of the base105 of the lens block 101 is put on respective cutout portions 103 aA ofthe projecting portions 103 a formed on the lower case 103 to therebyposition the base 105. Incidentally, the projecting portion 103 a isprovided with a column-shaped rib 103 aB on its upper surface and with asquare rib 103 aC on its lateral face.

The pan plate spring 102 is provided with positioning holes 102 a andsquare holes 102 b. The positioning holes 102 a determine the positionof the pan plate spring 102. The square holes 102 b are adapted tosecure the pan plate spring 102. Further, the spring portions 102 c eachhaving such a shape as to press the lens block 101 are each formed onthe inside of the pan plate spring 102 by the corresponding cutoutportions 102 f.

The exterior cover 107 covers the lens block 101. The exterior cover 107is formed with a lens opening portion 107 b. The lens opening portion107 b is opened in the exterior cover 107 in a tilt-directional shiftingrange of the lens 108 c so that the lens 108 c may be exposed. As shownin FIGS. 14 and 15, lens case support portions 107 c are formed insidethe exterior cover 107. The lens case support portion 107 c has acircular surface, which corresponds to a circular surface of the slideportion 108 a of the lens case 108. In this way, the lens case 108 cansmoothly be shifted in the tilt direction.

Further, guide portions 107 e and restricting portions 107 d areprovided inside the exterior cover 107. When the exterior cover 107 issecured to the base 105, the guide portions 107 e come into contact withthe corresponding bent portions 106 b of the tilt, plate spring 106.While coming into contact with the guide portions 107 e, the bentportions 106 b are guided to the corresponding securing holes 107 a ofthe exterior cover 107. When the exterior cover 107 is secured to thebase 105, the restricting portions 107 d come into contact withcorresponding lateral surfaces of the bent portions 106 b of the tiltplate spring 106. The restricting portion 107 d restricts the outwardwidening of the bent portion 106 b. In this way, the guide portions 107e and the restricting portions 107 d smoothly guide the bent portions106 b of the tilt plate spring 106 into the corresponding securing holes107 a of the exterior cover 107.

<2. Assembling Method in the Embodiment>

A description is next given of a method of assembling the securitycamera 100 in the present embodiment.

The circuit board 104 is installed on the lower case 103. The circuitboard 104 is secured by a single screw not shown and the hooks 103 bformed on the lower case 103 shown in FIG. 4.

The base 105 of the lens block 101 is put on the cutout portions 103 aAformed on the projecting portions 103 a of the lower case 103.

The pan plate spring 102 is next covered to hold the base 105. Inaddition, the positioning holes 102 a are aligned with the correspondingcolumn-shaped ribs 103 aB shown in FIG. 7. Consequently, the position ofthe pan plate spring 102 is determined. Further, the pan plate spring102 is pushed so that the square holes 102 b are fitted to thecorresponding ribs 103 aC shown in FIG. 7. In this state, the pan platespring 102 holds the base 105 by means of the three spring portions 102c formed inside the pan plate spring 102. The spring portion 102 c has afunction of a cantilever thin-plate spring. Thus, the base 105 ispressed against the cutout portions 103 aA of the lower case 103 bymeans of the three spring portions 102 c.

There are a plurality of the methods of increasing or decreasing theelastic force of the pan plate spring 102 in the embodiment. The methodshave an advantage that it is easy to adjust the magnitude of the elasticforce. Examples of the method of increasing or decreasing the elasticforce include a method of increasing or decreasing the thickness of thepan plate spring 102, method of increasing or decreasing the hardness ofmaterial of the plate spring, a method of increasing or decreasing thesize of the spring portion 102 c, and a method of increasing ordecreasing the thickness of the outer circumferential portion 105 a ofthe base 105.

With the shape of the pan plate spring 102 in the present embodiment,the three retaining portions 102 e provided at nearly regular intervalson the cuter circumference of the circular portion 102 d are fitted tothe corresponding ribs 103 aC of the lower case 103. Consequently, theelastic force of the spring portions 102 c is applied to the squareholes 102 b of the three retaining portions 102 e. Therefore, the squareholes 102 b are individually subjected to force in a direction where thepan plate spring 102 comes free from the lower case 103 by the elasticforce caused by the spring portion 102 c closed to the associated squarehole 102 b. However, such forces pull each other because the threeretaining portions 102 e are connected to each other via the circularportion 102 d. Therefore, the pan plate spring 102 will not come freefrom the lower case 103. Thus, it is not necessary to secure the panplate spring 102 to the lower case 103 by means of screws or the like.

Further, with the above-mentioned configuration and the shape of the panplate spring 102, the mechanism for turning the lens block 101 in thepan direction (the arrow direction in FIG. 1) has only the base 105having such a shape that the lens case 108 will not slide in the pandirection on the base 105, and the pan plate spring 102. Therefore, acomplicated mechanism is not necessary unlike the traditional way andscrews or the like are not necessary to secure the pan plate spring 102.Thus, the security camera 100 can achieve space saving.

The lens case 108 is put on the base 105. The lens case 108 is formedwith the slide portions 108 a on both the lateral surfaces. The slideportions 108 a cause the lens case 108 to be turned in the tiltdirection. The base 105 is formed with the lens case support portions105 b shaped to receive the corresponding slide portions 108 a.

The tilt plate spring 106 is next inserted into the insertion holes 105c of the base 105 shown in FIG. 8 in the state where the bent portion106 a holds the projecting portion 108 b of the lens case 108.Incidentally, the tilt plate spring 106 is similarly inserted into thebase 105 also on the opposite surface side not shown in FIG. 8.

In this state, the lens case 108 and the base 105 are united with eachother via the tilt plate spring 106. Since the bent portion 106 a holdsthe projecting portion 108 b of the lens case 108, a thin-plate portionsupporting the bent portion 106 a serves as a cantilever thin-platespring. The elastic force of the thin-plate spring serves as a load whenthe lens case 108 is turned based on the slide portion 108 a. As aresult, the elastic force the tilt plate spring 106 serves as adapted tohold the lens 106 c at a position in the tilt direction.

Incidentally, if the slide portion 108 a and the projecting portion 108b are formed separately from each other, there is an advantage as below.The contact with the tilt plate spring 106 may damage the projectingportion 108 b of the lens case 108. Even in such a case, the slidesurface in the tilt direction is the surface of the slide portion 108 adifferent from the projecting portion 108 b coming into contact with thetilt plate spring 106. Therefore, the movement in the tilt direction canbe maintained. The slide portion 108 a having a greater diameter canstabilize the movement in the slide direction. The projecting portion108 b having a smaller diameter can downsize the tilt plate spring 106.

There are a plurality of the method of increasing or decreasing theelastic force of the tilt plate spring 106 in the present embodiment.The method has an advantage that it is easy to adjust the magnitude ofthe elastic force. Examples of the methods of increasing or decreasingthe elastic force include a method of increasing or decreasing thethickness of the tilt plate spring 106, a method of increasing ordecreasing the hardness of a material of the plate spring, a method ofincreasing or decreasing an bending angle of the bent portion 106 a, anda method of increasing or decreasing the diameter of the projectingportion 108 b of the lens case 108.

The tilt plate spring 106 is inserted in a direction perpendicular tothe vertical direction encountered during installation. The tilt platespring 106 presses the lens case 108 toward the base 105 side.Therefore, the tilt plate spring 106 will not come off in the verticaldirection encountered during the installation. On the other hand, thetilt plate spring 106 can easily be removed in the inserting direction.

Also another bent portion 106 b of the tilt plate spring 106 is suchthat a thin-plate portion supporting the bent portion 106 b serves as aplate spring. The bent portion 106 b is inserted into the securing hole107 a of the exterior cover 107. In this way, the exterior cover 107 isunited with the base 105. Also the insertion direction of the tilt platespring 106 into the securing hole 107 a is a direction perpendicular tothe vertical direction encountered during the installation.

With the configuration described above, the tilt plate spring 106 issecured by being held between the base 105 and the exterior cover 107.Thus, it is not necessary to secure the tilt plate spring 106 by meansof a screw or the like.

As above, the security camera 100 can be easily assembled only byoverlapping the lower case 103, the circuit board 104, the lens block101, and the pan plate spring 102 in order.

<3. Adjusting Method in the Embodiment>

A description is given of a method of adjusting the lens 108 c of thesecurity camera 100 in the present embodiment.

[Pan Direction]

If the lens block 101 is to be manually turned in the pan directionindicated with arrows in FIG. 1, the spring portion 102 c of the panplate spring 102 serves as a load. If the lens block 101 is turned by aforce equal to or greater than the load and one's hand is released fromthe lens block 101 when the lens 108 c faces a desired direction, thelens 108 c is stopped at the position. The holding force of the lensblock 101 in this state corresponds to the elastic force of the springportion 102 c of the pan plate spring 102.

The elastic force is increased or decreased by the plurality of methodsas described above, which are simple. In the embodiment, elastic forceis studied as the rotational moment of the lens block 101 and set at 50to 100 Nmm. This value is determined depending on the weight, size andthe like of the lens block 101. Therefore, the fact that there is aplurality of the methods of increasing or decreasing the elastic forceis very effective for commercialization of products.

[Tilt Direction]

If the lens block 101 is to be manually turned in the tilt directionindicated with arrows in FIG. 2, the elastic force of the bent portion106 a of the tilt plate spring 106 serves as a load. If the lens block101 is turned by a force equal to or greater than the load and one'shand is released from the lens block 101 when the lens 108 c faces adesired direction, the lens 108 c is stopped at the position. The forcefor holding the lens block 101 in this state corresponds to the elasticforce of the bent portion 106 a of the tilt plate spring 106.

The elastic force is increased or decreased by the plurality of methodsas described above, which are simple. In the embodiment, the elasticforce is studied as the rotational moment of the lens block 101 and setat 10 to 40 Nmm. This value is determined depending on the weight, sizeand the like of the lens block 101. Therefore, fact that there is aplurality of the methods of increasing or decreasing the elastic forceis very effective for commercialization of products.

According to the embodiment described above, the security camera 100 issuch that the mechanism for shifting the lens 108 c in the tilt and pandirections does not have large component parts and can be realized by asmall number of component parts compared with traditional securitycameras. In addition, the security camera 100 does not need a fasteningscrew and is assembled only by overlapping the component parts from onedirection and more easily than before. As a result, the presentembodiment can realize the security camera reduced in cost and in size.

The present disclosure contains subject matter related to that disclosedin Japanese Priority Patent Application JP 2010-241255 filed in theJapan Patent Office on Oct. 27, 2010, the entire content of which ishereby incorporated by reference.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alternations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

1. An imaging device comprising: a lens case on which a lens isinstalled; a columnar member having a central axis coincidental with arotational axis of the lens case and formed on a lateral surface of thelens case, the rotational axis extending in a tilt direction being anin-plane direction perpendicular to a horizontal direction; a basesupporting the lens case so as to be turnable in the tilt direction; anda plate spring secured to the base and pressing a circumferentialsurface of the columnar member toward the base by elastic force. 2-9.(canceled)